Chemistry
by eightbitbat
Summary: What happens when two volatile elements combine.
1. Pepper

Pepper knew that something had changed.

She couldn't define it, but something was different. Tony put on a brave face, acted mostly like his old self, but something was off.

She couldn't imagine what it had been like, what he had gone through. To fight off aliens, sacrifice yourself for the good of others, fall from a portal to space into the arms of an enormous rage monster. It had to change a person. Still, she didn't think that was all there was to it.

After Thor took Loki back to Asgard, Tony brought Dr. Banner back to Stark Tower with him. Pepper was overwhelmingly busy in those first days, so she kept missing the chance to properly meet him. She barely had time to see Tony, and that ended up being just a few drinks while they discussed the tower reconstruction before she was called away to handle another company crisis.

Six days after Banner had come to stay at the tower, Tony came to her office and insisted the three of them go to lunch.

He perched on the edge of her desk. "Miss Potts, you are spending _entirely_ too much time here. You're coming to lunch with us, today. I insist you get away from all this work. You've been missing out on getting to know Bruce, too."

"Mister Stark, I have been up here running _your_ company and trying to get this place rebuilt. I will, however, make some time for lunch today. I do want to finally meet him."

She got up to give him a kiss, but he was already on his way out of her office, grinning. Over his shoulder, he said, "Great! Lobby, one p.m., Thai."

* * *

When she reached the lobby, Tony and Bruce were already waiting for her. She found that interesting, as Tony had never been on time for anything in his life. Pepper decided it must have been Bruce to get Tony down on time, and she was impressed that he had been able to swing that. Tony was notoriously difficult to manage.

Walking over to them, Bruce caught sight of her first. The little she knew of him fell into two categories: he turned into the Hulk, and he was a genius. Tony himself was a genius, and not modest about it, so for him to sincerely apply that term to another person was significant. She smiled at him as she approached and extended her hand.

"Dr. Banner, it's a pleasure to finally meet you," she said. His handshake was firm but not crushing, his hands dry and calloused. He gave her a shy smile.

"Please, Miss Potts, call me Bruce."

"Then Bruce, that's the last time you get to call me Miss Potts!" He gave a silent laugh, and Tony grinned at them both. "So, Tony, you said something about lunch?"

He motioned them toward the entrance. "Happy has the limo waiting out front for us. Bruce, there is this great Thai place on 42nd that I've been _dying_ to take you to."

"Great, I love Thai food. I spent a few months in Thailand shortly after…" He broke off and looked away, and Pepper realized he must mean after his accident.

"Study anything interesting while you were there?" Tony asked, not giving an awkward moment the chance to develop.

"Actually, yeah, there was this little biology lab…"

After that, the two men descended (or was it ascended?) into technical banter way above Pepper's head. By now they were getting into the limo, and Pepper sat on the side, letting the two settle into the seat, amused at how they so easily slipped into seemingly another language, just one that happened to use the same conjunctions. Bruce made some sort of joke, at least that's what Pepper thought it must be, from the way Tony chuckled and clapped him on the shoulder.

Tony was a demonstrative guy, but something in that touch made a little something go click in Pepper's brain. Watching Bruce and Tony together was almost hypnotizing, with their bright eyes and quick smiles. She didn't think she had ever seen Tony have such a connection with somebody.

The thought made her pause. Did she even have such a connection with Tony? Sure, they had chemistry, but this was something on an entirely different level.

They arrived at the restaurant and were shown to a booth. Pepper sat on one side and Bruce the other, Tony motioning the other man to scoot in so he could sit next to him. They picked up their bantering again, though she noted that they were now talking astrophysics instead of some sort of biology. They didn't seem to be intentionally excluding her from the conversation, they were just so wrapped up in each other to notice that she wasn't participating. It was fine with Pepper; she wanted the freedom to observe what was going on without notice.

If they were this intense at lunch, what would it be like in the bedroom?

Had they been together? She watched for a few moments, judging their reactions to each other, and decided that they hadn't. She had worked for and with Tony long enough to see sexual tension in him. Now that she had seen it, she could see it crackle off both men like electricity. No, nothing had happened yet, but both wanted it to, even if they hadn't admitted it to themselves yet – or each other. Well, Tony knew, at least. _That_ was what had changed. It wasn't saving the world or nearly dying in the process. It was this, this meeting of someone, which had changed him.

The waiter came and took their orders. Now Tony and Bruce had moved on to joking about Thor's hair. Pepper cast her mind back through the last week and realized that not only had she and Tony not slept together since the battle, they hadn't even shared a bed. He did have the tendency to crash on the floor in one of the labs when he got caught up in a particularly interesting project, and she had been working such long hours that she hadn't always made it to bed, the couch in her office being much closer, so she hadn't even noticed.

This is the end of us, she thought sadly. How could it be anything but that? What she was witnessing, these two, this went beyond chemistry. This was something deeper. This was…cellular.

It was at that moment that Tony looked up and caught her gaze and held it. For a second, he looked so open, so vulnerable. His eyes said, _I love you, I am so sorry, but I need this_. He looked even more vulnerable than the time they had argued about him being Iron Man, about how he thought he had been spared for a reason.

Her brow furrowed slightly, but she gave a small smile, too, one that she hoped would convey _I love you too, I understand. Go to him. Be happy._

Before Bruce noticed them, the moment was over, and shortly thereafter their food arrived. With eating slowing down their brains, the two men conversed like normal people again, and Pepper put her feelings aside and enjoyed a pleasant lunch with them.

* * *

The three of them chatted amiably on the ride back to the tower. They climbed into an elevator and Tony punched two buttons, one to take the two men to the labs, the other for Pepper's office, which was on a higher floor.

When the doors dinged and opened, Bruce walked through, and Tony started to follow. Pepper tugged on his sleeve to stop him. If it had to happen, it may as well happen right away. Tony couldn't be happy with pretending, and now that Pepper knew she couldn't either.

Without even looking back to see what she wanted Tony called to Bruce, telling him he would catch up. The doors dinged and closed.

They rode to her floor, passed her assistant at his desk, and made it into her office all without saying a word. Tony paced, full of anxious energy.

She sighed and went to sit on the couch. "It's ok."

"Is it? Is it really?" His questions were rhetorical.

"Does he know?"

Tony did another lap around her office and then collapsed into a chair, head in hands, the picture of angst. "I don't know," he mumbled.

"Did you ask him? Has it ever come up?"

"No. Not what needs to, anyway. We've talked about him being here, how he doesn't need to worry about running ever again, of course, but getting from 'Come hang at my place' to 'I want your dick in my mouth' is a different story. "

That stung. She didn't know how to respond to it. Tony was self-involved, sure, but was what they had going to go without even a whimper before she had to start offering advice on how to get into Bruce's pants?

For once, Tony knew he'd been an ass. He sighed and got up, joining her on the couch. He took her hand and said, "I'm sorry. You have got to know that I didn't plan this, not in any way. It just…"

"Happened. Yes, I can see that. I suppose I should be thankful that we had as much time together as we did. I've seen you go through an entire calendar of girls in the same amount of time that we've been together."

He gave her an apologetic look. "For what it's worth, you're worth more than two calendars of girls."

"Yes, I know." He smiled and squeezed her hand. "So, can I ask? Why him? What happened?"

Tony got up and resumed his pacing. "I don't know. I read his file and thought, hey, finally Fury brings along someone I can talk to. Then I met him. He was jumpier on the helicarrier, worried that the Hulk would come out, hating himself for having a part of him be so dangerous. Shaking hands with him was like taking a jolt to the arc reactor," he strummed his fingers on his chest as he stopped pacing and looked out the window. "I don't know what it was. I just know what it is."

There it was. At least he admitted it to himself. Now he just had to do the same to Bruce. For Tony's sake, she hoped he felt the same, but seeing the way they interacted, she didn't think that would be a problem.

"So, what are you going to do about it?"

"Fuck, I don't know. He's so…fragile. For something so strong, he's amazingly fragile. I don't want to do anything that would scare him away, and I think the wrong word could send him to a million pieces."

"A million pieces? Like…the Hulk?"

Tony made a dismissive sound. "The Hulk is the last thing on my mind."

"So, it doesn't bother you that at a moment's notice he could…?"

"Pepper, it's not like that. He's a man, he's not the monster, and he's acquired far more control than he lets on. No, it's not the Hulk I'm concerned about. It's the man."

"Well…do you want me to talk to him?" Tony turned and stared at her. Finally it looked like she was speaking a language _he_ didn't understand. "Ok, maybe not."

"I'll…figure something out. I have to."


	2. Bruce

He had promised himself he wouldn't stay. He had been surprised and pleased that Tony had been serious in his offer to come to Stark Tower. After the battle he had been high on their win, actually allowing himself to try on feelings like _accepted_ and _successful_ and _belonging_ for a change. He knew it wouldn't last, it couldn't last, and that he'd soon enough be off and alone again, trying his best to keep his head above water and not destroy anything. So, he let Tony talk him into staying, let him lead him to an impossibly shiny convertible, got into the passenger seat and went along.

Each day felt like both a miracle and a mistake. Never before had Bruce felt so welcome in a place, even before his accident. Tony truly did not see him as a man with a monster inside. Instead, he saw him just as a man. He treated Bruce like a complete equal, with none of the legendary Stark ego or preening. It was easy, comfortable. They were just scientists, and friends, building shit and making shit and blowing shit up. It was…fun.

Which was a problem.

Fun led to attachments. Attachments led to emotions. Emotions led to…the other guy. The other guy led to Bruce fleeing the country and starting from scratch, again, alone with his pain. As much as he tried to avoid it, these things happened, and he knew he had a decent layer of emotional scarring to prevent anything from penetrating too deep.

Bruce had come to the conclusion that Tony was taking his emotional scarring as a personal challenge. Conscious or not (and, in Bruce's estimation, Tony didn't do anything at all without conscious forethought), Tony was needling and insinuating himself past every barrier Bruce had created. One of the problems with this was that when things went south, and things always went south, he didn't know if he could pick himself up again this time.

Why was Tony doing it? Try as he might, Bruce couldn't figure out Tony's angle here.

At night when he was trying to fall asleep in the overly-large bed in his new apartment in Stark Tower, he let his mind and heart wander. In the dark, he imagined a life for himself, a life without having to always think about what might cause an incident, what he might lose this time. In the dark, he was free to do whatever he wanted with his life, no longer bound by any restraints. He had done this for years, waiting until he was safely behind closed eyes before thinking about what he was missing out on, but for the first time, what he thought about in the dark was the same as what he had.

At first, they were simple dreams. Staying at the tower. Doing stuff in the lab. Hanging out, watching movies, cooking. Tony seemed to make his way into even those early fantasies, but as he spent so much of each day with Tony, Bruce paid it no mind. After a bit, the fantasies became more complex. Staying in one place long enough to decorate it and make it his own. Making major discoveries with Tony and being able to get them out into the world, to help people in a way he never could before. Being happy. Living a normal life.

One night, he was letting himself imagine such a future and he drifted off to sleep. His mind kept going, however, and he was actually dreaming of what he and Tony would accomplish. In the dream, he pushed the last piece of the design into place. Tony, standing next to him, beamed at him and declared it perfect. Then Tony kissed him. In the dream, this was perfectly normal. It was natural to celebrate an important discovery by kissing the man you loved.

Now _that_ part of the dream had Bruce sitting up in a cold sweat. Love? Love?

Love.

_Get ahold of yourself, Banner_, he told himself sternly. Tony was amazing, but it would be stupid to think of him like that on SO many different levels. First off, Tony was straight. Well. Tony was involved with Pepper, which was more important. A small, unhelpful voice in Bruce's head whispered things he had read about Tony Stark's infamous love life in the past. "Adventurous" was probably a more applicable label for Tony than "straight". _Still doesn't do anything about Pepper_, he told the small voice.

More importantly, Bruce had no idea what indulging in these sorts of strong emotions would do to the other guy. He already ran a high enough risk of something happening and the Hulk coming out without adding matters of the heart into the mixture. In his younger days, he was able to balance a burning passion for science with a burning passion for life. He had had his fair share of affairs with lovely women – and one summer spent holed up with his research assistant, a college boy named Charles with the bluest eyes he'd ever seen, unable to get enough of each other's bodies. Each affair had been such a torrent of feelings; he shied away from thinking about how fast that might bring on the other guy.

Bruce forced the thoughts out of his mind, forced himself to lie down and run through some breathing exercises. Eventually he was able to get back to sleep, but the sleep was restless, and in the morning he wondered if his troubles were beginning again. Maybe it was time to give up on this moment of surreal calm in his life, get out before the storm broke over him again.

* * *

The mood in the lab that day was subdued. Bruce hadn't seen Tony since they went to lunch with Pepper the day before. After lunch Bruce had headed back to the lab, and he'd received a text from Tony saying that he was held up in some Stark Industries business and would catch him later. Bruce had continued what he'd been working on that morning, and had spent the evening reading, comfortable but oddly lonely without the constant energy of Tony nearby.

Today that energy was…out of focus. Bruce knew that he had his own baggage this morning, but something was up with Tony, as well. He was uncharacteristically quiet; the only sounds from him were his occasionally banging something around and swearing. He was pleasant enough to Bruce when they crossed paths, but more than once, he felt Tony's eyes on him, his expression tense.

Could Tony read him that well, to know that he was thinking of leaving? He hoped he wasn't that transparent. Finally, he took a deep breath, scrubbed a hand over his face, and went over to the workbench Tony was slouched over. Tony looked up at him, at first glance happy if distracted, though he quickly sensed something was up and the tense expression returned.

Before Bruce could say anything, Tony held up a hand to stop him. "Don't. Just don't."

"Don't what?"

"You're about to tell me you're leaving, aren't you?"

Bruce sighed. Yep, transparent. Tony could read that, but could he read the other thing, too? "Tony -"

"Are you unhappy here? Unhappy with me?"

"What? No! It's just -"

Tony stood up and turned to face him, eyes dark and shining. "Just what, Bruce? You're running again. You don't need to run, ever again."

Tony's eyes were going right through him. Bruce took a deep breath and tried to strengthen his resolve, but standing this close Bruce could smell him, musk and sweat and grease and solder. "I…uh…I'm not running, I'm…"

"I'm just going to cut you off again. You know how I know you're running? Because you're not articulating. You are one of the most articulate men I know, but when you're evading, you stumble. Come up with a solid argument next time." He clapped his hands on Bruce's shoulders, gripping them for just a second before releasing him and turning him towards the elevator. "Until then, my friend, you aren't going anywhere. Except to the bar."

The brief contact and Tony's unbreakable confidence staggered him. "Uh, okay. Wait, the bar?"

"Yeah. I have some sorrows to drown."

"Oh?"

"Pepper and I broke up yesterday."

"Oh."

To the bar it was, then.


	3. Tony

It was dark, so very, very dark.

And it was cold, a dry, bone-numbing cold.

He was insignificant. A speck. A blip in eternity.

And he was falling.

* * *

Someone was shaking him. "Tony. Tony, wake up."

His eyes opened and he gasped, remembering the end of his nightmare. Falling. He jerked a bit, tried to sit up, but there was an arm on his chest. It was heavy and reassuring.

It was Bruce's.

Tony raised a hand and scrubbed it across his face. "What happened? Where are we?"

In the dim light from his arc reactor he could see Bruce, lying next to him, head raised. He could just make out a smile. "Whiskey happened. A lot of it. You were pretty smashed, so I got you to your room, but I was pretty smashed too, I guess." They were on Tony's massive bed, though fully clothed, the bed still made. "I woke up when I heard you…talking in your sleep, I guess. Nightmare?"

"Yeah."

"Wanna talk about it?"

Tony knew that Bruce would understand, but he didn't think he was ready to delve too deep into the damage left from the battle just yet. Also, the haze from the nightmare was fading due to the distractingly warm arm still on his chest. "Do you ever get them?"

"Yeah. I don't know that I know what it's like not to have them." The cool, dim light brought out the angles in his face, the circles under his eyes. Not as bad as when Tony had first met him, but still there, marking him as a person with a burden he could never put down. "I don't like talking about them either."

Bruce's arm tensed, as though he was going to remove it, and Tony's hand shot up and grabbed it by the wrist. He looked at the other man and saw no fear there, nothing that said he was going to be scared off by anything Tony did. Instead, he smiled at the pressure Tony had put on his wrist, and dropped his head down onto the pillow. Tony could feel the heat of him, Bruce's chest not quite against his arm. "Go back to sleep, Tony."

"Thanks."

Bruce didn't reply, but his hand shifted a bit on Tony's chest, fingers grazing the circle of the arc reactor, and then settling comfortably on his sternum. Tony didn't remove his hand.

They slept.

* * *

When Tony woke again, it was slowly. Even before he opened his eyes, he wished he had his sunglasses handy. This was going to be one killer hangover.

Bruce was still there. At some point in the night they had shifted, and Tony opened his eyes to find his head buried in Bruce's chest, their arms and legs entangled. This was a good sign, right? Tony tried not to move, not to wake Bruce, so he could take a moment to process this.

Bruce had taken care of him when he was sloppy drunk (he didn't want to think of how he'd probably embarrassed himself, if not the both of them, at that point; he had no illusions about how bad he got when he was wasted). Bruce had also taken care of him after a bitch of a nightmare. He'd also stayed in Tony's bed all night, but not like a friend or a brother. Tony wouldn't have to move far to be wrapped around the other man. This was good. Bruce wouldn't still be here, arm around Tony and snoring slightly, if he wasn't interested, right? Or at least open to suggestion?

Tony shifted carefully, still trying not to wake the other man, so he could see Bruce's face. In sleep he looked more relaxed than Tony thought possible, the lines etched into his face by time and stress eased. He was scruffier than Tony usually saw him, probably a few days since he'd shaved. His curly hair, streaked grey here and there, was sleep tousled, and Tony practically twitched from wanting to bury his hands in it. He got a sudden mental image of Bruce, on his knees in front of him, looking up at him with those brown eyes, putting his hands in that curly hair while Bruce's hands fumbled with his zipper…

He had to take a deep breath to stifle the noise that wanted to escape his mouth, and that was all it took to wake Bruce. He blinked his eyes a half-dozen times, trying to focus and take in his surroundings. He didn't seem surprised at how intertwined they were. He tilted his head up and looked at Tony.

"Morning, sunshine," he said, trying not to grin too hard.

A small smile curved Bruce's lips in return. "Morning, Tony."

"Sleep well?"

"Yeah."

Given their entanglement, Tony had no way of hiding his arousal from Bruce – he could feel his erection pressing into the other man's thigh. "Look, Bruce. I'm not going to play games here. I think you have an idea of what's on my mind." Bruce didn't say anything, but he didn't stop smiling either. Instead, he blushed.

Tony took that as a cue and pressed forward to kiss him. Slowly at first, giving Bruce an out, in case there was any misunderstanding his intent. There wasn't. Bruce hesitated only for a second before melting under his mouth and pulling Tony even closer, one hand into his hair, the other on his ass. A surge of lust swept through him, and he arched his back and pressed onto Bruce. He freed a hand from behind Bruce's head and it went straight down and palmed his erection. Definitely no misunderstandings there. When he pressed down Bruce gave a moan, and Tony started to slip his hand under the waistband of Bruce's pants.

His fingers barely grazed hot flesh when Bruce pulled away. He took a few shuddering breaths. "No Tony, we can't do this."

Tony pulled back instantly and looked questioningly at Bruce. "What's wrong?"

Bruce pulled back a bit further, taking his hands off of Tony and rubbing them over his face and through his hair. "I don't think I can do this."

"You're not interested?"

Bruce shook his head. "No, not that. More than interested. Too interested."

Tony frowned at him, "Help me out here, buddy. What's wrong?"

"I...Tony, look, I don't know if doing this will bring out the other guy, and I don't want to hurt you."

There it was. Bruce looked away, pained, but Tony wasn't giving up just yet. He ran a hand along Bruce's chest. "You don't know?"

Bruce covered Tony's hand with one of his own, stilling it on his chest. "No. I haven't…not since the accident. It's too risky."

"You haven't tried it at all?"

"No."

"So…you're just hypothesizing?"

Bruce gave him a warning look. "Tony…"

"Well, you are, aren't you? Aren't we scientists? Geniuses? Shouldn't we be able to test your theory out?" He inched his face closer to Bruce's again. "Test it, disprove it, or failing that, find a way to work around it? Any theory must be fully tested before accepted as fact. Tested thoroughly and scientifically…"

Bruce took a deep breath, but didn't push Tony away again. He sighed. "People have been trying to get me in a lab and study me for years now, but not quite in that way."

"Then I get bonus points for thinking of it first." He dropped his face down and nuzzled the line of Bruce's jaw, feeling the scruff against his lips and tongue.

"No publishing your findings!" Tony nipped at his neck in response. Bruce put a hand on his shoulder to draw his attention back to the conversation. "Serious, Tony, we can't fuck around with this. We have to go slow."

Tony smirked at Bruce. "If my theories are correct, fucking around is exactly what I intend to do. Serious. Though I've never heard you say fuck before. You know how hot that is?"

"Fuck you," he said, though his eyes were bright with laughter.

"Mmm." Tony kissed him again then, slowly, hands in almost respectable places (though he couldn't help the one that ran up into Bruce's hair). He broke off and looked Bruce in the eye. "There. Perfect gentleman. Well, nearly. We'll go as slow as you need Bruce. We'll figure this one out." He sat up, giving Bruce's shoulder a strong squeeze. "Come on, let's go get some breakfast. I need to clear away this hangover and start planning exactly how to fuck you until you can't walk." He hopped out of bed and headed towards the kitchen, the sound of Bruce's shocked laughter following him out.


	4. Bruce ii

Two weeks had passed and Tony was doing an admirable job with his theories. They had been taking things slow but always moving forward, and Bruce had yet to do or feel anything he had to worry about. The anger was there, it was always there, but it stayed put safely in the back of his head. In some ways, it felt like what they did helped him keep the anger in check. Bruce hoped it stayed that way.

While he and Tony hadn't actually had sex yet, much of Tony's theory testing involved them making out all the time like a couple of teenage boys. They set no restrictions, but Tony always seemed to know when Bruce was starting to worry. Their sessions meant the two of them ended up in various parts of Stark Tower in various stages of undress. Tony was practically an exhibitionist, but Bruce was shyer, and he didn't look forward to running into that cleaning lady again.

Pepper walking in on them seemed like a horrible inevitability. To his surprise, when it happened it hadn't been as bad as he'd feared. Tony had explained to Bruce why he and Pepper had split, and that it was very mutual and they were still friends, but Bruce couldn't help but feel some measure of guilt for the part he had played in it, so he had kept his distance. At least, he had stayed away from her, but he couldn't prevent her from walking in on him and Tony making out in a supply closet. She had looked a little shocked, a little annoyed, but mostly amused. Tony said something about her needing to order more staples and she just shook her head and closed the door again. He didn't know what she did after that, because as soon as the door closed Tony had put his hands in Bruce's hair, and it had been impossible to focus on anything other than the very talented mouth of Tony Stark for quite some time after.

Last night was the first time they had spent the night in the same bed again. That was one delay Bruce had pressed for, as waking up with his arms full of Tony had almost been too much to handle last time. So, they worked their way up to it, and last night had been a fantastic test for their project. He still wasn't sure where kissing Tony had stopped and sleep had started, or where sleep had stopped and kissing Tony had started, but he wasn't too worried about it.

Bruce couldn't decide if was surprised or not at Tony's patience with him. Surprised because he didn't think the manic Tony would be able to reign himself in that long. Two things seemed to temper him, though. One was that he genuinely seemed to care for Bruce. He could see that in him, all the time. Bruce had since given up trying to deny to himself that he was in love with Tony, and strongly suspected the feeling was mutual. Tony actually didn't act any different towards Bruce than he had from the moment they met; Bruce just noticed it more and more each day.

The second thing that kept Tony patient was one of the things that drove him in the first place: his rabid curiosity. At the moment, his project was to prove or disprove Bruce's ability to have sex with him without ending up as the Hulk, so Tony was focused on testing every aspect of sexuality and stimuli he could think of. He didn't go around constantly badgering Bruce for make out sessions, but his mind was engaged in solving this problem, and Bruce knew that he would dedicate himself to the task for as long as it took.

Bruce was at a workstation in the corner of the lab when Steve got there. He was there to see Tony about some prototype motorcycle Tony was building for him. Bruce waved at Steven when he came in, but he was more interested in his files than talk about motorcycles, so he quickly lost himself in his equations again.

After a while, he noticed it had gotten quiet again, and he looked up to see Steve sitting on a nearby stool, watching him work. Tony was nowhere to be seen. Steve sensed his question before he could voice it. "He went to go check on something. He'll be back in a few."

"Oh, ok. How've you been, Steve?"

"Not too bad. Getting my apartment in Brooklyn fixed up. I think I'm finally starting to get a feel for the neighborhood. I mean, the current neighborhood, not the way it was."

"Good, that's good to hear."

Steve squinted at Bruce's display but then shook his head, not understanding the computations he was working on. "Here using Stark's computers?"

Did Steve not know Bruce was living here? "Something like that."

"Stark does have really slick toys, I'll give him that. He's working on a new bike for me."

"Yeah, so I've heard. That sounds cool."

"Yeah. So, where did you end up? Somewhere in the city, right, if you're hanging out here?"

"Well, yeah. I ended up here."

"Manhattan?"

"No, I live here in the tower now. Tony set me up with an apartment in the building."

"Huh! That was nice of him."

"Yeah, it was."

Steve had been watching Bruce as they talked, and then narrowed his eyes at something. "Is that a…hickey?"

Bruce could feel color rushing to his face. How hard _had_ Tony been chewing on his neck this morning? He tried to focus on the computer's display. "Uh, no idea."

"No, right there, on your neck." Steve was quiet for a moment. "Is that really such a good idea?"

This took Bruce by surprise, and he looked up to see Steve giving him a stern look. "Excuse me?"

"You know what I mean. Is messing around with girls really the best way to go about things? You know…for safety reasons?"

Bruce carefully set down the notebook he had in his hand, and then took off his glasses and set them on the counter. "Steve, that is none of your business."

"It is if you end up endangering people."

"After all we've been through, you still think I'm that much of a danger? You think I'd put people in danger with my actions?"

"Hey, Banner, I'm just being-"

"What you're doing, _Captain_, is overstepping. This is none of your business, and that's the end of discussion." He turned to walk away and Steve got up and put a hand on his shoulder to stop him.

"Bruce, wait, you're being reckless here."

Keeping a tight hold on his anger, he turned around and punched Steve in the face. It was just a gesture. He knew that unless he let the other guy out, it would take a lot more than his fist to even mark the skin of Captain America, but he needed to make it clear to Steve that this was out of line. For a second, Steve looked concerned – Bruce Banner getting physical was a sure sign that the Hulk was about to make an appearance.

Of course, Tony had walked back into the lab in time to see Bruce punch Steve. "What the _hell_ did I miss?" Bruce just sighed and brushed past him, leaving the lab.


	5. Tony ii

Tony couldn't believe what he just saw. He left for five minutes and came back to his boyfriend punching _Captain Fucking America_ (never mind how hot that was). What the fuck had happened to drive Bruce to violence, but not drive him far enough to bring out the other guy?

Once Bruce left the lab, Steve turned to him and sighed, but Tony didn't even let him get a word out. "What the hell, Steve? What did you say to him?"

Now Steve looked annoyed. "Seriously? You see him punch me and you ask me what _I_ did?"

"Yep. No question. Bruce could have wiped the floor with you had he really wanted, but clearly he was sending you a message – which means you put your big Captainy boot in your mouth in some spectacular way."

"I don't know about that, I was just worried. He's messing around and people could get hurt."

Ah. Steve had figured it out. "Steve, what Bruce and I do is none of your business, and no one is going to get hurt. Leave him alone."

"No Tony, not what you and Bruce do here…he had marks on his neck, I think him messing around with girls could be dangerous…"

Or maybe he hadn't. "Ok, Captain Oblivious, listen. I left those marks on his neck, there are no girls, and there is no danger. We've been working carefully to make sure everything we do is responsible, though if I'm not mistaken, you've undone all our hard work in about thirty seconds. That man has more self-control than either of us can imagine and you just spit in his face."

Steve looked completely stunned. He sank down onto the stool behind him and just sat silent for a moment. "Banner and…you?"

"Yeah. Something so hard to believe about that?" Tony knew the forties were a different time, but he really hoped Steve was above casual homophobia.

"No, it's…it's just unexpected, that's all. I thought you had a girlfriend? Or do you still?"

Tony shook his head. "Did. Pepper. We ended it after Loki, when I knew that, well, Bruce existed."

Steve stared down at his hands for a few minutes. "Well. Well, I'm just a total ass, aren't I? I don't even know why I felt the need to press him on it. I just had this mental image…"

"Yeah, don't worry, he does too. That's why we've been so careful about it, and now who knows? I hope I can save some of our progress."

"Stark, I'm sorry. I should have known better. I trust Bruce, and I trust you." He got up and looked around the lab. "Where do you think he's gone? I want to apologize."

"Probably not the best idea. Let him cool down. I have a feeling I know where he is, but seeing you might…make things worse. I'll talk to him, and you can make it up to him later."

"Okay. I'll leave you to that then. And again…sorry."

After Steve made his way out of the lab, Tony headed up to the top of his tower, to his penthouse. He was hoping Bruce had made his way there to cool off. He was right, and Bruce was leaning against one of the newly-replaced glass windows, not far from the Loki-shaped dent he'd left in the floor. Tony hadn't had that fixed yet, and wasn't sure he wanted to. It was a nice memento.

Bruce had his arm on the glass, and was resting his head on his arm, staring out over the city. He didn't look over when Tony came to stand next to him. Tony didn't speak; he just slung his arm across Bruce's shoulders and leaned into him. "Steve's an asshole. He knows it."

"I'd say he had a point, but you'd just argue with me. I know he's an asshole. I'm glad he does too. It just really fucking hurt, to hear that he thought so little-"

"Yeah, he's seen the error of his ways. I helped."

"Well, that tongue of yours can do miraculous things."

Before Tony could reply, Bruce turned and started walking away.

"Where are you going?"

"Bed."

"Bruce, it's three in the afternoon."

Bruce stopped and half-turned towards Tony, looking at him with those bottomless brown eyes. "I know."

Tony smiled and followed his lover into the bedroom.


	6. Bruce iii

Bruce stretched on his back on the bed, warmed from the sun spilling through the floor-to-ceiling windows. Tony lay on his stomach, head turned to study Bruce. The sheets were twisted and wrinkled around them. Bruce took a deep breath and the world was reduced to a place that was just the scent of them, their skin, sweat, and sex, mixing and mingling into something new and wondrous. Bruce rolled onto his side to face Tony and reached an arm out to place a hand on the small of his back. "I love you, you know."

Tony smiled that smile that Bruce knew was only for him. That smile that said he was calm yet on fire all at once. It was very much the same smile he had given Bruce when they had first talked, back in the lab on the helicarrier, less than a month but more than a lifetime ago. "I love you too."

He pulled Tony close against his body, tucking his lover's head under his chin. He felt the quiet thrum of the arc reactor against his chest. No other words needed to be said.

* * *

_I do not love you as if you were salt-rose, or topaz,  
or the arrow of carnations the fire shoots off.  
I love you as certain dark things are to be loved,  
in secret, between the shadow and the soul._

_I love you as the plant that never blooms  
but carries in itself the light of hidden flowers;  
thanks to your love a certain solid fragrance,  
risen from the earth, lives darkly in my body._

_I love you without knowing how, or when, or from where.  
I love you straightforwardly, without complexities or pride;  
so I love you because I know no other way_

_than this: where I does not exist, nor you,  
so close that your hand on my chest is my hand,  
so close that your eyes close as I fall asleep._

Sonnet XVII  
Pablo Neruda


End file.
